/*
 * Copyright 2016 SoChishun.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package util;

import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 *
 * @author SoChishun
 * @see http://blog.sina.com.cn/s/blog_4a4f9fb50100se03.html
 */
public class VersionStringComparator implements Comparator<String> {

    public int compare(String s1, String s2) {
        if (s1 == null && s2 == null) {
            return 0;
        } else if (s1 == null) {
            return -1;
        } else if (s2 == null) {
            return 1;
        }

        String[] arr1 = s1.split("[^a-zA-Z0-9]+"), arr2 = s2.split("[^a-zA-Z0-9]+");
        int i1, i2, i3;
        for (int ii = 0, max = Math.min(arr1.length, arr2.length);
                ii <= max; ii++) {
            if (ii == arr1.length) {
                return ii == arr2.length ? 0 : -1;
            } else if (ii == arr2.length) {
                return 1;
            }
            try {
                i1 = Integer.parseInt(arr1[ii]);
            } catch (Exception x) {
                i1 = Integer.MAX_VALUE;
            }
            try {
                i2 = Integer.parseInt(arr2[ii]);
            } catch (Exception x) {
                i2 = Integer.MAX_VALUE;
            }
            if (i1 != i2) {
                return i1 - i2;
            }
            i3 = arr1[ii].compareTo(arr2[ii]);
            if (i3 != 0) {
                return i3;
            }
        }
        return 0;
    }

    // 测试 2016-6-9
    public void test() {
        String[] data = new String[]{
            "2.0",
            "1.5.1",
            "10.1.2.0",
            "9.0.0.0",
            "2.0.0.16",
            "1.6.0_07",
            "1.6.0_07-b06",
            "1.6.0_6",
            "1.6.0_07-b07",
            "1.6.0_08-a06",
            "5.10",
            "Generic_127127-11",
            "Generic_127127-13"
        };

        List<String> list = Arrays.asList(data);
        Collections.sort(list, new VersionStringComparator());

        for (String s : list) {
            System.out.println(s);
        }
        /*
        <output>
            1.5.1
            1.6.0_6
            1.6.0_07
            1.6.0_07-b06
            1.6.0_07-b07
            1.6.0_08-a06
            2.0
            2.0.0.16
            5.10
            9.0.0.0
            10.1.2.0
            Generic_127127-11
            Generic_127127-13
        </output>
         */
    }
}
